It’s natural to worry about side effects when starting any new lupus treatment. For example, one MyLupusTeam member expressed concern about weight gain after their doctor switched them from azathioprine (Imuran) to mycophenolate mofetil (CellCept): “The azathioprine has helped me lose some of the weight prednisone has packed on and made my joints feel better overall. I was hoping mycophenolate would continue the luck.”

Putting on unwanted pounds because of taking medication can have a big impact on your physical and mental health. Although everyone responds differently to medications, it can be helpful to know what to expect before starting a new treatment.

Mycophenolate for Lupus

Mycophenolate — either mycophenolate mofetil or mycophenolate sodium (Myfortic) — can be used to stop and prevent lupus flares in people with systemic lupus erythematosus (SLE). The drug works by weakening the immune system to keep it from attacking healthy tissue around your body. You might be prescribed mycophenolate if you have severe lupus symptoms that cause problems with major organs like your kidneys, brain, heart, or lungs. It’s most often taken by people with kidney problems caused by lupus, which is called lupus nephritis.

Mycophenolate is known as a steroid-sparing treatment — it allows you to decrease your dose of corticosteroids like prednisone. A lower dose of prednisone can reduce the risk of possible, sometimes serious side effects such as:

• Weight gain
• Mood changes
• Osteoporosis (thinning bones)
• Eye problems
• Muscle weakness
• Heart disease
• Stomach problems

Mycophenolate Side Effects

Although taking mycophenolate can tamp down steroid-related side effects, it has unwanted effects of its own, which vary from person to person. Some people don’t develop any mycophenolate-related problems, while others may have side effects severe enough to stop the medication. However, mycophenolate is generally well tolerated.

The most common side effects of mycophenolate are diarrhea, nausea, and vomiting, as well as a low white blood cell count. Other possible side effects include:

• Trouble falling asleep or staying asleep
• Hypertension (high blood pressure)
• Rash
• Headache
• Muscle or joint pain
• Tremors (uncontrolled shaking)
• Skin sensations of tingling or burning
• Swollen hands, lower legs, or feet

More serious side effects of mycophenolate include:

• Greater risk of infection
• Increased risk of cancers such as lymphoma and skin cancer
• Severe stomach pain and intestinal bleeding (characterized by vomiting or coughing up blood that looks like coffee grounds, as well as bloody or black, tarry stools)
• Fever and/or muscle pain not caused by infection

Mycophenolate and Weight Changes

Researchers have observed weight loss and weight gain in clinical trials for mycophenolate, though fewer than 20 percent of participants have experienced either side effect.

Several MyLupusTeam members reported that mycophenolate didn’t cause weight gain. One member said, “I’ve been on mycophenolate since May 2015. It has not affected my weight.” Another commented, “I’ve been on mycophenolate for years and didn’t gain weight.”

Although there’s no research into how mycophenolate might affect your weight, some of its side effects can cause weight changes.

Mycophenolate and Weight Gain

Mycophenolate could cause swelling in your hands, lower legs, ankles, or feet, which is known as peripheral edema. In clinical trials, between 27 percent and 64 percent of people experienced this side effect. Symptoms of peripheral edema include:

• Puffiness or swelling just below the skin
• Shiny, stretched-looking skin
• Pitting edema (skin holding a dimple after being pressed)
• Heavy feeling in legs or arms

If you notice any abnormal swelling, it’s important to contact your doctor right away. Swelling can also be a sign of other serious medical conditions, such as heart, kidney, or liver disease or damage to your veins.

Mycophenolate and Weight Loss

Mycophenolate can cause stomach-related side effects that could contribute to weight loss, such as nausea, vomiting, and loss of appetite. Unexplained weight loss could also be a sign of some cancers. Because mycophenolate brings a very rare side effect of increased cancer risks, talk to your doctor if you lose weight without trying.

Other Causes of Weight Gain in Lupus

Between 28 percent and 50 percent of people with lupus worldwide have obesity, similar to or slightly higher than is seen in general populations. However, weight gain can have a bigger impact on people with lupus. Studies show that weight gain can be riskier for people with lupus than for those without lupus.

People with lupus may be more likely to have a higher body weight because of certain factors, such as:

• Steroid use — Taking these medications can lead to increased appetite and weight gain.
• Low physical activity — Lupus symptoms like fatigue, stiffness, and pain can make it hard to stay active.
• Thyroid disease — Hypothyroidism (the thyroid gland doesn’t make enough thyroid hormone) is more common in people with lupus and is associated with weight gain.
• Low vitamin D — It’s common for people with lupus to lack vitamin D, a deficiency that is linked with a high body weight.

Managing Your Weight During Lupus Treatment

Talk with your health care provider if you’re concerned about weight changes. It’s important to seek medical advice before making any major changes to your diet or exercise regimen.

Choose Healthy Foods

There isn’t one specific diet for lupus, but focusing on nutritious foods can help you manage your weight, ease lupus symptoms, and improve your overall health. Strive for a balanced diet that includes:

• Plenty of fruits and vegetables
• Lean protein, including chicken, fish, egg whites, beans, peas, lentils, and tofu
• Whole grains like whole-wheat bread and brown rice
• Healthy fats like olive oil and avocados

Stay as Active as Your Lupus Allows

Lupus symptoms can make it difficult to engage in regular exercise, but — surprising as it may seem — physical activity can actually improve issues like fatigue and joint pain.

It can be tough to get started, but it helps to choose an activity that fits well with both your routine and your physical abilities. Anything that gets you moving can help, whether that means taking a walk, going for a bike ride or a swim, or practicing a low-impact routine such as yoga.

Be Mindful of Your Medications

If you feel that your medication is causing weight gain, ask your rheumatologist about switching to a different type. The many lupus treatment options include antimalarial drugs like hydroxychloroquine (Plaquenil), immunosuppressants like methotrexate, and biologics like belimumab (Benlysta).

It might take some trial and error, but you and your health care provider can find the right regimen to help you manage your lupus and sidestep side effects as much as possible.

Talk With Others Who Understand

MyLupusTeam is the social network for people with lupus and their loved ones. On MyLupusTeam, more than 223,000 members come together to ask questions, give advice, and share their stories with others who understand life with lupus.

Have you taken mycophenolate for lupus? Have any of your lupus treatments caused weight gain? Share your experience in the comments below, or start a conversation by posting on your Activities page.